In X-ray examination tables, it is common to make a patient-supporting table top move in relation to a fixed element such as the pedestal of the examining table, for example. The motion is generally got through actuation by driving means, which are integrally joined to the pedestal, the rotational movement of these driving means being transformed into a linear movement which is transmitted to the table top by a system of pulleys and belts. In general, a driving shaft is made to rotate on its axis and, by means of at least one cogged wheel, it drives one or more belts the ends of which are fixed to the table top which has to be moved. The belts move about against different pulleys, and the motion of the belts drives the motion of the table top.
The table top is moved on supporting means such as, for example, firstly, an element that is mobile along the longitudinal axis and fixed to one end of the table top, and, secondly, a roller set under the table top along an axis which is crosswise to the length of the table top. These supporting means may also comprise supporting rollers only, set along axes which are crosswise to the length of the table top, at least two supporting rollers being needed if their length substantially corresponds to the width of the table top. Furthermore, reaction rollers must be set on the longitudinal sides of the table top, in reaction to each roller.
These various pulleys, various rollers and various reaction rollers are held by supporting shafts which are integrally joined with the fixed part of the table--i.e., with the pedestal.
One of the problems raised by these supporting shafts, owing to their number, is the fact that, as a result of their careful distribution, the pedestal acquires a large dimension parallel to the longitudinal axis of the table top. This large dimension of the pedestal constitutes, in most cases, an irksome feature, especially in examination tables with movable table tops where, firstly, there has to be easy access to the patient and, secondly, the maximum amount of space must be left unoccupied for setting up the various X-ray instruments.
Moreover, the proliferation of these supporting shafts considerably increases the cost of the examination table.